CN112578638A

CN112578638A - Photoetching method, photoetching device and computer readable storage medium

Info

Publication number: CN112578638A
Application number: CN201910931297.6A
Authority: CN
Inventors: 王津洲
Original assignee: SiEn Qingdao Integrated Circuits Co Ltd
Current assignee: SiEn Qingdao Integrated Circuits Co Ltd
Priority date: 2019-09-29
Filing date: 2019-09-29
Publication date: 2021-03-30
Anticipated expiration: 2039-09-29
Also published as: CN112578638B

Abstract

The invention provides a photoetching method, a photoetching device and a computer readable storage medium, wherein the method adjusts a photoetching machine according to the ratio of the size of a design substrate of the photoetching machine to the size of a substrate to be processed so as to form a target pattern on the substrate to be processed through the design mask original edition. Therefore, wafers with different sizes can be subjected to photoetching by using the design reticle of the photoetching machine in the same photoetching machine, for example, 8-inch and 6-inch wafers can be subjected to photoetching on an 8-inch photoetching machine. In addition, the method of the invention does not need to modify or replace the hardware of the photoetching machine, but realizes the photoetching of wafers with different sizes by the same photoetching machine by adjusting the vertical distance among the design mask original plate of the photoetching machine, the substrate bearing device and the projection objective lens of the photoetching machine, and forms target patterns on the wafers, thereby not increasing the production cost on the premise of ensuring the yield of wafer preparation and having good economic benefit.

Description

Photoetching method, photoetching device and computer readable storage medium

Technical Field

The present invention relates to the field of semiconductor manufacturing, and more particularly, to the field of shared integrated circuit design and manufacturing, and more particularly, to a photolithography method, a photolithography apparatus, and a computer-readable storage medium.

Background

In an integrated circuit design fabrication process, a photolithography process of a substrate (e.g., a wafer) is a fundamental process of semiconductor fabrication, and a photolithography machine is an important photolithography apparatus in the fundamental process. A lithography machine typically includes an optical system, a mask stage system, a projection objective system, a substrate transport system, a stage, etc. And a lithography machine is generally suitable for lithography of only one size of wafer. Such as a 6-inch wafer lithography machine, an 8-inch wafer lithography machine, a 12-inch wafer lithography machine, etc., which are commonly used in the market. Wafer lithography machines of different sizes cannot share in common.

With the scale of integrated circuit production, the limitation of the lithography machine only suitable for single-size wafers becomes more and more obvious, for example, the limitation of tape-out and verification of original integrated circuit design and the production efficiency of subsequent factories are restricted, and further the economic benefit is influenced. If the hardware modification of the lithography machine is performed, the cost is increased, so that a lithography method suitable for wafers with different sizes is urgently needed to adapt to the trend of designing and manufacturing the shared integrated circuit.

Disclosure of Invention

In order to overcome the limitation of the lithography machine in the manufacturing of wafers with different sizes in the prior art, the invention provides a lithography method, a lithography device and a computer readable storage medium. The method can be used for photoetching wafers with different sizes on the same photoetching machine, so that the utilization rate of the photoetching machine is improved, the development of new products is accelerated, and the production efficiency is improved.

According to a first aspect of the invention, there is provided a lithographic method comprising the steps of:

respectively placing a substrate to be processed and a design mask original edition of a photoetching machine on a substrate bearing device and a mask platform of the photoetching machine;

adjusting the photoetching machine according to the ratio of the size of the design substrate of the photoetching machine to the size of the substrate to be processed so as to form a target pattern on the substrate to be processed through the design reticle;

wherein adjusting the lithography machine comprises adjusting at least one of the design reticle, the substrate carrier and the projection objective of the lithography machine to adjust a vertical distance between the design reticle, the substrate carrier and the projection objective of the lithography machine such that the design reticle forms a target pattern on the substrate to be processed in a ratio between the size of the design substrate and the size of the substrate to be processed.

Optionally, the substrates to be processed have different sizes.

Optionally, the ratio of the size of the design substrate to the size of the substrate to be processed is 1: 1-4: 3.

Optionally, the design substrate and the substrate to be processed include wafers.

Optionally, the design substrate comprises an 8 "wafer.

Optionally, the substrate to be processed includes a 6 "wafer.

Optionally, adjusting the lithography machine according to the ratio between the size of the design substrate of the lithography machine and the size of the substrate to be processed to form the target pattern on the substrate to be processed through the design reticle further comprises:

and horizontally moving the design mask original plate along the size range of the substrate to be processed until the substrate to be processed is photoetched.

According to a second aspect of the present invention, there is provided a lithographic apparatus comprising an exposure system, a mask stage system, a substrate carrier, a substrate transport system, and a focus alignment system, the exposure system comprising an optical system and a projection objective, the focus alignment system comprising a first control module, a second control module, and a third control module,

the substrate transmission system and the mask platform system are respectively used for placing a substrate to be processed and a design mask original edition of the photoetching machine on a substrate bearing device and a mask platform of the photoetching machine;

the focusing and aligning system adjusts the photoetching machine according to the ratio of the size of a design substrate of the photoetching machine to the size of the substrate to be processed so as to form a target pattern on the substrate to be processed through the design mask original edition;

the first control module is used for adjusting the vertical distance between the projection objective lens and a substrate to be processed on the substrate bearing device;

the second control module is used for adjusting a mask stage in the mask stage system so as to adjust the vertical distance of the design reticle on the mask stage relative to the projection objective and/or the substrate to be processed;

the third module is used for adjusting the substrate bearing device so as to adjust the distance between the substrate to be processed and the projection objective and/or the design reticle.

Optionally, the lithographic apparatus further comprises a processor and a memory;

the memory is used for storing one or more computer programs;

the processor is used for running one or more computer programs to execute the photoetching method.

According to a third aspect of the invention, a computer readable storage medium having one or more computer programs stored thereon; wherein a computer program is run by one or more processors for performing the method of the invention.

As described above, the lithography method, the lithography apparatus, and the computer-readable storage medium according to the present invention have the following advantageous effects:

according to the photoetching method, the photoetching machine is adjusted according to the ratio of the size of a design substrate of the photoetching machine to the size of the substrate to be processed, so that a target pattern is formed on the substrate to be processed through the design mask original edition; for example, adjusting the lithographic machine comprises adjusting at least one of the design reticle, the substrate carrier and the projection objective of the lithographic machine to adjust the vertical distance between the design reticle, the substrate carrier and the projection objective of the lithographic machine such that the design reticle forms the target pattern on the substrate to be processed in a ratio between the size of the design substrate and the size of the substrate to be processed. Therefore, the wafers with different sizes can be photoetched by using the design mask original plate of the photoetching machine in the same photoetching machine, for example, 8-inch and 6-inch wafers can be photoetched on an 8-inch photoetching machine, so that the sharing of the photoetching machine is realized in a certain range, the utilization rate of the photoetching machine is improved, the development of a new product is accelerated, and the production efficiency is improved.

In addition, the method does not need to modify or replace the hardware of the photoetching machine, but realizes the photoetching of different wafers by adjusting the vertical distance among the design mask original plate of the photoetching machine, the substrate bearing device and the projection objective lens of the photoetching machine, and forms the required target pattern on the wafers.

Drawings

The features and advantages of the present invention will be more clearly understood by reference to the accompanying drawings, which are illustrative and not to be construed as limiting the invention in any way, and in which:

FIG. 1 is a flow chart illustrating a photolithography method according to an embodiment of the present invention.

FIG. 2 is a diameter relationship diagram of a 6 "wafer and an 8" wafer.

Fig. 3 is a schematic diagram of a design reticle for an 8 "wafer.

Fig. 4 is a schematic diagram of a partial pattern formed on an 8 "wafer by the design reticle shown in fig. 3.

FIG. 5 is a schematic view of reticle patterns formed by scaling down the design reticle shown in FIG. 3.

Fig. 6 is a schematic diagram of a portion of a pattern formed on a 6 "wafer using the design reticle shown in fig. 3.

FIG. 7 is a schematic diagram of a functional module of a lithographic apparatus according to a second embodiment of the invention.

FIG. 8 is a schematic diagram showing the connection between a processor and a memory in the lithographic apparatus of the present invention.

Reference numerals

1016 inch wafer

1028 inch wafer

103 design reticle

103' design of reticle pattern after reticle scaling

Partial pattern on 1048 inch wafer

Partial pattern on 104' 6 inch wafer

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention.

In the following embodiments of the present invention, words indicating orientations, such as "upper", "lower", "left", "right", "horizontal", "vertical", etc., are referred to only to enable those skilled in the art to better understand the present invention, and should not be construed as limiting the present invention.

Example one

In photolithography processes, reticles and reticles are very common tools for forming patterns or patterns on a substrate. The function of the mask is to copy the pattern on the mask onto the whole substrate or another mask in a corresponding manner at a time through the exposure process. The reticle is a reticle in which a pattern included in the reticle is transferred to the entire substrate or another photomask in a Step & Repeat (Step & Repeat) manner.

Whether the mask exposure or the reticle step and repeat exposure is performed, the substrate size for which the general lithography machine is designed is constant and fixed.

The present embodiment provides a photolithography method by which the same photolithography machine can be applied to substrates of different sizes. As shown in fig. 1, the photolithography method of the present invention includes the steps of:

In this embodiment, the substrate may be a wafer that usually needs to be subjected to photolithography, and may be, for example, a silicon wafer, a silicon carbide wafer, a lithium tantalate wafer, a gallium nitride substrate wafer, or the like.

In this embodiment, the above method is described in detail by taking an example in which a 6-inch wafer is subjected to photolithography on a 8-inch wafer photolithography machine.

As shown in FIG. 2, the ratio of the diameter of the 6 "wafer 101 (diameter 150mm, thickness 675 μm) to the 8" wafer 102 (diameter 200mm, thickness 725 μm) is D1: d2 was 3: 4. When the 8-inch wafer 102 is subjected to lithography, the 8-inch wafer 102 is placed on a substrate carrier of a lithography machine, and then a design reticle of the lithography machine, i.e., the design reticle 103 for the 8-inch wafer 102 shown in fig. 3, is adjusted to a default position of the lithography machine, while the projection objective is adjusted to a design state. Then, the 8-inch wafer 102 is subjected to photolithography, for example, by moving the design reticle 103 in a step-and-repeat manner within a horizontal plane within the size range of the 8-inch wafer, and the pattern on the design reticle 103 is copied onto the 8-inch wafer 102 until the entire 8-inch wafer 102 is subjected to photolithography to form a complete pattern. Fig. 4 shows a schematic diagram of a partial pattern formed on an 8 "wafer by designing a reticle.

When 6 "wafer is photo-etched, the 6" wafer 101 is also placed on the substrate carrier of the photo-etching machine of 8 "wafer 103, and the diameter ratio of the 6" wafer 101 to the 8 "wafer 102 is D1: d2 is 3:4, and the lithography machine is adjusted based on the ratio of 3:4 such that the reticle 103 is designed to shrink by the ratio of 3:4 to accommodate the target pattern to be formed on the 6 "wafer surface. In a preferred embodiment, the relative vertical distance between the design reticle, the substrate carrier and the projection objective is adjustable, after the 6 "wafer is placed on the substrate carrier, the design reticle 103 can be scaled down by adjusting at least one of the design reticle, the substrate carrier and the projection objective, the pattern of the reticle 103 that can be replicated onto the 6" wafer after scaling down is shown as the reticle pattern 103' in fig. 5, and then the design reticle 103 is moved in a horizontal plane within the size range of the 6 "wafer, again in a step and repeat manner, and the pattern on the design reticle 103 is replicated onto the 6" wafer 101 until the entire 6 "wafer 102 is finished being lithographically patterned to form a complete pattern. As shown in fig. 6, a schematic diagram of a target pattern formed on a 6 "wafer by an 8" wafer lithography machine and a design reticle is shown, in which only a portion of the pattern 104' is shown.

According to the method, hardware of the photoetching machine does not need to be improved or replaced, and the vertical distance between the design mask original plate of the photoetching machine, the substrate bearing device and the projection objective lens of the photoetching machine is adjusted to realize photoetching of different wafers and form the required target pattern on the wafers.

Example two

The embodiment provides a lithography apparatus, and as shown in fig. 7, a schematic diagram of functional modules of the lithography apparatus is shown, where the lithography apparatus includes an exposure system, a mask stage system, a substrate carrying device, a substrate transport system, and a focus adjustment and alignment system, where the exposure system includes an optical system and a projection objective, and the focus adjustment and alignment system includes a first control module, a second control module, and a third control module.

The substrate conveying system conveys and places the substrate to be processed on a substrate carrying device of the lithography machine in the lithography preparation stage, and the mask stage system places the design reticle on the mask stage in the lithography preparation stage. And the focusing and aligning system adjusts the photoetching machine according to the ratio of the size of the design substrate of the photoetching machine to the size of the substrate to be processed so as to form a target pattern on the substrate to be processed by designing the mask original plate.

In a preferred embodiment of the present invention, the first control module of the focus alignment system is configured to adjust a vertical distance between the projection objective and a substrate to be processed on the substrate carrier; the second control module is used for adjusting the vertical distance of the design reticle on the mask stage in the mask stage system relative to the projection objective and/or the substrate to be processed; the third module is used for adjusting the substrate bearing device so as to adjust the distance between the substrate to be processed and the projection objective and/or the design reticle.

In a preferred embodiment of this embodiment, as shown in fig. 8, the lithographic apparatus further includes a processor and a memory connected by a bus, the memory stores one or more computer programs, and the processor can run the one or more computer programs to perform the lithographic method according to the first embodiment of the present invention.

In a preferred embodiment of this embodiment, the substrate to be processed includes a wafer, which may be, for example, a silicon wafer, a silicon carbide wafer, a lithium tantalate wafer, or a gallium nitride substrate wafer. And the substrate to be processed may be a different size wafer, such as an 8 "wafer, a 6" wafer, etc.

The embodiment takes a lithography machine with 8-inch wafer as an example, and is described in detail with reference to fig. 2 to 6.

When an 8-inch wafer is subjected to photoetching by using an 8-inch wafer photoetching machine, the 8-inch wafer 102 is placed on a substrate bearing device of the photoetching machine by a substrate transmission system, a mask platform system places a design mask original edition on a mask platform, and a focusing alignment system adjusts the photoetching machine, specifically, a projection objective, the design mask original edition and the substrate bearing device are respectively adjusted to the design position of the 8-inch wafer photoetching machine by a first control module, a second control module and a third control module. Then, the 8-inch wafer 102 is subjected to photolithography, for example, by moving the design reticle 103 in a step-and-repeat manner within a horizontal plane within the size range of the 8-inch wafer, and the pattern on the design reticle 103 is copied onto the 8-inch wafer 102 until the entire 8-inch wafer 102 is subjected to photolithography to form a complete pattern. Fig. 4 shows a schematic diagram of a partial pattern formed on an 8 "wafer by designing a reticle.

When an 8-inch wafer photoetching machine is used for photoetching a 6-inch wafer, the substrate transmission system places the 6-inch wafer 101 on a substrate carrying device of the photoetching machine, and the center position of the wafer 101 is aligned with the center position of the substrate carrying device. The mask stage system places a design reticle on the mask stage, and the focus alignment system adjusts the lithography machine, specifically, the lithography machine is adjusted by at least one of the following methods: the first control module adjusts the vertical distance of the projection objective relative to a to-be-processed substrate on the substrate bearing device, the second control module adjusts the vertical distance of a design reticle on a reticle stage in the reticle stage system relative to the projection objective and/or the to-be-processed substrate, and the third control module adjusts the substrate bearing device to adjust the distance of the to-be-processed substrate relative to the projection objective and/or the design reticle. By the above adjustment, the reticle is designed to be reduced in size as a whole in a 3:4 ratio of the 6-inch wafer to the 8-inch wafer, and a reticle pattern 103' that can be transferred to the 6-inch wafer is formed as shown in fig. 5. After the adjustment is completed, the 6-inch wafer 101 is subjected to photolithography, for example, the design reticle 103 may be moved in a step-and-repeat manner in a horizontal plane within the size range of the 6-inch wafer, and the reticle pattern 103' with the reduced pattern on the design reticle 103 is copied onto the 6-inch wafer 101 until the entire 6-inch wafer 101 is subjected to photolithography to form a complete pattern. Fig. 6 shows a schematic view of a part of a pattern formed on a 6 "wafer by designing a reticle.

In a preferred embodiment of the present embodiment, the adjustment of the lithography machine is implemented by a processor executing a computer program in a memory. The memory may include, but is not limited to, high speed random access memory, non-volatile memory. Such as one or more magnetic disk storage devices, flash memory devices, or other non-volatile solid-state storage devices.

The Processor may be a general-purpose Processor, and includes a Central Processing Unit (CPU), a Network Processor (NP), and the like; the Integrated Circuit may also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, discrete gate or transistor logic device, or discrete hardware components.

In addition, various computer programs referred to in the present disclosure may be loaded onto a computer-readable storage medium, which may include, but is not limited to, floppy diskettes, optical disks, CD-ROMs (compact disk-read only memory), magneto-optical disks, ROMs (read-only memory), RAMs (random access memory), EPROMs (erasable programmable read-only memory), EEPROMs (electrically erasable programmable read-only memory), magnetic or optical cards, flash memory, or other medium/machine-readable medium suitable for storing machine-executable instructions. The computer readable storage medium may be a product that is not accessed by the computer device or may be a component that is used by an accessed computer device.

In particular implementations, the computer programs are routines, programs, objects, components, data structures, etc. that execute particular orders or implement particular abstract data item properties.

This embodiment only exemplarily describes an 8-inch wafer lithography machine for performing lithography on a 6-inch wafer, and realizes 6-inch wafer and 8-inch wafer shared lithography. It should be understood that other sizes of wafers may be shared by the lithography machine in accordance with the method and apparatus of the present invention within the adjustability of the lithography machine.

As described in the above embodiments, the lithography method, the lithography apparatus, and the computer-readable storage medium of the present invention have the following advantageous effects:

The foregoing embodiments are merely illustrative of the principles of this invention and its efficacy, rather than limiting it, and various modifications and variations can be made by those skilled in the art without departing from the spirit and scope of the invention, which is defined in the appended claims.

Claims

1. A lithographic method, comprising the steps of:

2. The lithographic method of claim 1, wherein the substrates to be processed have different dimensions.

3. The lithography method according to claim 1 or 2, wherein a ratio between the size of the design substrate and the size of the substrate to be processed is in a range of 1:1 to 4: 3.

4. The lithographic method of claim 3, wherein the design substrate and the substrate to be processed comprise wafers.

5. The lithographic method of claim 4, wherein the design substrate comprises an 8 "wafer.

6. The lithographic method of claim 5, wherein the substrate to be processed comprises a 6 "wafer.

7. The lithography method according to claim 1, wherein adjusting said lithography machine to form a target pattern on said substrate to be processed through said design reticle according to a ratio between a size of a design substrate of said lithography machine and a size of said substrate to be processed further comprises the steps of:

8. A photoetching device is characterized by comprising an exposure system, a mask platform system, a substrate bearing device, a substrate transmission system and a focusing and aligning system, wherein the exposure system comprises an optical system and a projection objective, the focusing and aligning system comprises a first control module, a second control module and a third control module,

9. The lithographic apparatus of claim 8, further comprising a processor and a memory;

the memory is used for storing one or more computer programs;

the processor is configured to run one or more computer programs to perform the lithographic method of any of claims 1-7.

10. A computer-readable storage medium having one or more computer programs stored thereon; a computer program for performing the method of any one of claims 1 to 7 when executed by one or more processors.